Your search resulted in 236 documents. Displaying 25 entries per page.
A Novel Type of Multiple Cavity Attack in Wood Cell Walls of Heat-treated Timber Exposed in Seawater – Preliminary Observations
2004 - IRG/WP 04-10523
Samples of untreated and heat-treated Norway spruce and Douglas fir were submerged in Langstone Harbour, Portsmouth for 4 years at a depth of ca. 0.3 metres. The heat-treated samples had been prepared using the Plato process. Samples were initially assessed for the severity of marine borer damage and were then examined microscopically for evidence of microbial decay. Longitudinal and transverse wo...
R A Eaton, C Björdal, T Nilsson
Formosan Subterranean Termite Resistance to Heat Treatment of Scots Pine and Norway Spruce
2003 - IRG/WP 03-40264
New challenges to the durability of wood building materials have arisen in the U.S. The Formosan subterranean termite (Coptotermes formosanus Shiraki) now infests sizable portions of the U.S. south and their range is extending. Heat treatments offer a unique opportunity for wood-based composites because many of the process techniques already employ various thermal applications and could be easil...
W R Smith, A O Rapp, C R Welzbacher, J E Winandy
Assessment of untreated Papua New Guinean timbers against subterranean termites. Progress Report 1
1990 - IRG/WP 1436
Eight major commercial timber species (Intsia palembanica, Pometia pinnata, Homalium foetidum, Dracontomelon dao, Calophyllum spp., Eucalyptus deglupta, Nothofagus spp., and Alstonia scholaris) were exposed in ground contact against termites. Five replicates of heartwood stakes of 25x25x250 mm³ of each species were randomly embedded in the soil. Results after 24 months exposure showed that Kwila ...
M Rokova, H C Konabe
Implications for comparability of laboratory experiments revealed in studies on the effects of population density on the vigour in groups of Coptotermes lacteus (Froggatt) and Nasutitermes exitiosus(Hill) (Isoptera: Rhinotermitidae, Termitidae)
1983 - IRG/WP 1197
(Summary of paper 1194)
The vigour - survival and wood consumption - of groups of Coptotermes lacteus and Nasutitermes exitiosus was measured when termites were kept at different population densities (g termites/ mL) by changing group size and/or volume of the holding container. A characteristic pattern emerged. At low population densities (< 0,01 g/mL) performance of termites improved with an increase in group size; at higher population densities it tended to decline. The impact of altering group size and container volume on termite vigour was most pronounced at low densities; at higher population densities, performance tended to be more stable but declined markedly when termites became overcrowded. In most jar-type experiments on termites, especially those conducted in Europe and the U.S.A., small groups of termites are housed in disproportionately large jars, resulting in very low, sub-optimal population densities. Suggestions are made for improvements in experimental design that would lead to an enhancement of the comparability of results from different laboratories.
M Lenz, R A Barrett, E R Williams
Social and economocal impact of an extension of service life resulting of an adequate preventive treatment. Application to wooden components used in urban areas with a high density of population
1993 - IRG/WP 93-50001-15
Le document évalue les problèmes rencontrés en zone urbaine pour le sauvetage des constructions: coordination de la lutte, délimination des chantieres et des périmètres d'investigation, nuisances causées par les interventions, risques pour la santé, risques pour l'environnement. Coûts. Comparaison socio-économique du traitement préventif et des interventions à posteri...
A T De Lelis, G A C Lopez
Blue Staining of Coated Modified and Unmodified Wood
2006 - IRG/WP 06-10589
We investigated resistance of unmodified, DMDHEU modified and oil heat treated uncoated and coated Scots pine wood against blue stain fungi. Both EN 152-1 and the reverse exposure tests showed excellent resistance of DMDHEU and especially of oil heat treated wood against blue staining. It is not needed to add any additional protective coating layers to prevent modified wood from staining. However,...
M Petric, M Pavlic, M Humar, M Tomažic
Termite Response to Oil-Heat-Treated Norway spruce, Scots Pine and Eucalyptus Wood
2006 - IRG/WP 06-20325
The work here presented focused on the behaviour of subterranean termites (Reticulitermes grassei Clément) towards Oil-Heat-Treated (OHT) Norway spruce (Picea abies L.), Scots pine (Pinus sylvestris L.) and eucalyptus (Eucalyptus globulus Labill) wood, with a particular interest in the development of simple methods adequate to study the resistence of these materials to termite attack. Small test ...
L Nunes, T Nobre, C Welzbacher, A O Rapp
Identification of fungi colonising coated and modified wood exposed outdoors using sequencing and T-RFLP profiling
2006 - IRG/WP 06-20326
Wood decay and staining fungi are known to colonize coated and modified wood. Rapid and reliable ways of identifying fungi on coated and modified wood may improve diagnostics and product development. In this work nine fungi growing in painted wood panels exposed outdoors at a test field in Uppsala, Sweden, were identified using sequencing and T-RFLP (Terminal Restriction Fragment Length Polymorphi...
U Råberg, J Bijelovic, C J Land, S Bardage, N Terziev
Heat treatment of less-valuable Nigerian-grown Ceiba pentandra wood for improved properties
2006 - IRG/WP 06-40332
The hardwood Ceiba pentandra locally known as “ araba “ in Nigeria is rarely used for structural and construction works due to its high dimensional instability, low strength and durability values. Samples (10 x 10 x 150mm) were removed from four green boards (25 x 200 x 3000mm) of this species originating from a natural forest stand in Nigeria and subjected to 2-hour heat treatment at 160°C a...
L Awoyemi
Improvement of Grevillea robusta durability using heat treatment
2006 - IRG/WP 06-40333
Heat treatment of Grevillea robusta was carried-out under inert conditions to improve its durability. Resistance of heat treated samples was evaluated by malt agar block tests after three months of exposure to several wood rotting fungi. Results showed that the fungal durability was greatly improved after treatment. There was a good correlation between fungal resistance and mass loss which is a fa...
F Mburu, S Dumarçay, F Huber, M Petrissans, P Gérardin
Wood plastic composites from modified wood; Part 1 - Conceptual idea, mechanical and physical properties
2006 - IRG/WP 06-40338
Wood plastic composites, WPCs, are rapidly taking shares from preservative treated wood on the decking market. However, the long term performance of the WPC products in this application is uncertain. Therefore, in an attempt to increase the long term performance and durability, the substitution of the unmodified wood component with modified wood has been studied in the work presented in this paper...
P Larsson Brelid, B K Segerholm, M Westin, M E P Wålinder
The Effect of Flavonoids on Colour and Spectral Changes of the Wood Surface Caused by Heat Treatment or Ultra-violet Irradiation
2006 - IRG/WP 06-40341
Both heat treatment and UV irradiation can cause discolouration and change in the spectral properties of wood surface. Some of the characteristic flavonols have significant role on colour and spectral changes, despite of their relative small quantities in wood.
Colour changes and spectral properties of natural and extracted black locust (Robinia pseudoacacia L.) and poplar (Populus nigra L.) were...
R Csonka-Rákosa, L Molnár-Hamvas, E Börcsök, J Molnár, K Németh
Assessment of the Envelope Effect of Three Hot Oil Treatments: Resistance to Decay by Coniophora puteana and Postia placenta
2006 - IRG/WP 06-40344
Timber of Corsican pine (Pinus nigra var. maritima) and Norway spruce (Picea abies) was treated in hot linseed oil, rapeseed oil and a proprietary resin derived from linseed oil. The samples were immersed in oil or resin under reduced pressure at temperatures of 180°C and 200°C. Very high uptakes of the oils or resin were recorded for pine, while spruce showed lower weight percent gains, below...
M J Spear, C A S Hill, S F Curling, D Jones, M D C Hale
Protection of a low-density mangrove timber species gewa (Excoecaria agallocha) through preparation of particleboard – An Assessment
2006 - IRG/WP 06-40348
It is now well established that the conversion of low-density and low-cost timbers into laminated, composite and densified form is an alternative of wood protection by means of wood preservatives. Once only the timber species gewa (Excoecaria agallocha) was used for manufacturing newsprint paper in Bangladesh, which is not continued today. The feasibility of commercial production of particleboard ...
A A Mahfuz, M O Hannan, M A Islam, M N Islam , M M Islam, A K Lahiry
Comparative studies on penetration and retention of CCA (C) and creosote in wood from APHID-killed and sound Kenyan-grown Mexican cypress (Cupressus lusitanica)
2006 - IRG/WP 06-40352
Properties of wood from Kenyan-grown Mexican cypress (Cupressus lusitanica), attacked and killed by the cypress aphid (Cinara cupressi), in terms of density and treatability, were investigated in comparison to the properties of wood from sound trees. Density in small wood samples from aphid-killed trees was found lower than density in samples from sound trees, and reduced with tree age in samples...
R Venkatasamy, F M Opar
Wood plastic composites from modified wood. Part 2 - Durability in laboratory decay tests
2006 - IRG/WP 06-40353
The decay resistance of wood plastic composites, WPCs, was tested according to modified versions of AWPA E10 (soil-block test) and ENV 807 (tests in three un-sterile soils, terrestrial microcosms, TMCs). The WPC materials were conically extruded profiles with 30% polypropylene content. The 70% wood content was untreated Scots pine sapwood, acetylated pine and heat treated Norway spruce, respective...
M Westin, P Larsson Brelid, M L Edlund, G Alfredsen
The influence of wood density on the durabilities of three Ghanaian hardwoods (Nauclea diderrichii (de Wild.) Merr., Nesogordonia papaverifera (A. Chev.) R. Capuron and Corynanthe pachyceras Welw.) )
2007 - IRG/WP 07-10603
Review of factors that influence wood durability shows that although density varies depending on stem position, its role on decay resistance appears controversial. The role density plays in influencing the durability of three hardwoods from Ghana, namely Nauclea diderrichii (de Wild.) Merr., Nesogordonia papaverifera (A. Chev.) R. Capuron) and Corynanthe pachyceras Welw. is therefore investigated ...
C Antwi-Boasiako, A J Pitman, J R Barnett
Effects of heat treatments on decay resistance and material properties of ponderosa pine and yellow poplar
2007 - IRG/WP 07-40374
The potential for using heat treatment to improve the properties of North American fenestration species was evaluated on ponderosa pine (Pinus ponderosa L) and yellow poplar (Liriodendron tulipifera L) treated using the ThermoWood process at various treatment temperatures and times. Soil block tests using Gloeophyllum trabeum, Postia placenta, or Trametes versicolor showed that durability was enh...
C Vidrine, C Freitag, J Nicholson, J J Morrell
Natural Weathering of Coated Oil Heat Treated Wood
2007 - IRG/WP 07-30440
Oil heat-treated (thermally modified) pine wood was coated with 9 different types of solvent- or water-borne exterior finishes. The systems with modified wood substrate as well as unpainted and painted non-modified controls were exposed to weathering (EN 927-3) on two locations with sub-alpine and alpine climate. The influence of natural ageing on surface systems was evaluated after one year of ex...
M Petric, B Kricej, M Pavlic, A Rapp
Mold resistance of heat-treated wood
2007 - IRG/WP 07-40358
The resistance of heat-treated sugi sapwood against three mold fungi was evaluated. Wood specimens were first subjected to heat treatments at 180 and 220ºC for 2 and 4 hours. Mold growth on the surface of the specimens was measured 1, 2, 4 and 6 weeks after the inoculation with the fungi in laboratory conditions. Laboratory decay tests were performed using two brown and white-rot fungi along with...
S N Kartal
Multivariate analysis of infrared spectra for the prediction of the mechanical performance and dimensional stability of thermally modified wood
2007 - IRG/WP 07-40367
The use of calibrated mid-infrared Fourier transform (FTIR) spectroscopy for predicting the main bending strength parameters of thermally modified wood is described for the first time. The analysis is based on the handling of OSC-filtered FTIR data from control and treated wood samples, using partial least squares (PLS) regression.
Sets of Norway spruce, Scots pine and Beech wood samples were th...
M M González-Peña, M D C Hale
Treatment of Green Logs infested by Exotic Pest: Case Study of the Emerald Ash Borer: Agrilus planipennis Fairmaire
2007 - IRG/WP 07-10628
Invasive alien insect species periodically infest forests in the United States causing the destruction of plant species and decimating populations, resulting in significant economic and ecological losses for areas involved. The Emerald Ash Borer (EAB) was first discovered on North American soil in the summer of 2002 near Detroit, Michigan and has since spread to several other Midwestern states and...
P Nzokou, S Tourtellot, D P Kamdem
White Rot in Eucalyptus Wood: Anatomical Changes and Density Variation by X-Ray Densitometry
2007 - IRG/WP 07-10631
Wood samples of the hybrid Eucalyptus grandis x urophylla attacked by white rot fungi were characterized. Microscopically, the colonization of the fungi was observed in the vessels and radial parenchyma, however the cell walls of the some fibers were attacked, indicating susceptibility to this fungi. Zone lines were observed as a result of interaction and compartmentalization of the fungi. Microsc...
M Tomazello Fo, S Brazolin, M P Chagas
Do insects infest wood packing material with bark following heat-treatment?
2007 - IRG/WP 07-10633
As a result of international trade, many bark- and wood-infesting insects are inadvertently transported in wood packing materials (WPM) such as crating, dunnage, and pallets. WPM is suspected as the likely pathway for most of these borers, although the exact mode of entry into the USA is unknown for all 25 borers. The top 10 countries of origin were, in decreasing order, Italy, Germany, China, Spa...
R A Haack, T R Petrice, P Nzokou, D P Kamdem
Fire Safety of Wood Floor Assembly: Model and Full-scale Test
2007 - IRG/WP 07-20375
The present paper describes the model for the prediction of fire safety of wood floor assemblies. The model includes heat transfer model for the calculation of the flow of heat in floor assembly and structural model for the analysis of the mechanical performance of wood joists. The floor assemblies considered in this paper are constructed with nominal 2x10 (38x241mm) wood joists lined by Type X ...
H Takeda